Joint for sheet-metal receptacles.



PATENTED SEPT. 29, 1903.

Y A. C.Y BADGBIL JOINT FOR SHEET METAL RECEPTAGLES.

APPLICATION FILED DEO. 11I 1901.

. N0 MODEL. H31 WTMBESEE.

NITED STATES Patented September 29, 1903.

PATENT OFFICE.

'.JOINT` FOR SHEET-METAL RECEPTACLES.

SPECIFICATION forming partl of Letters Patent No. 739,974, dated September 29, 1903.

Application filed December 11,1901. Serial No. 85.439. (No model.)

To all whom it may concern:

Be it known that I, ARTHUR O. BADGER, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Joints for Sheet- Metal Receptacles, of which the following is a specification.

This invention relates to sheet-metal receptaeles-such, for instance, as the bodies of chemical fire-extin guishers-designed to withstand a heavyinternal fluid-pressure; and its object is to strengthen the jointsbetween the portions of the sheet-metal walls of such receptacles. A common method of uniting the edges of themetalis by means of a doublelapped or interlocked soldered seam, and various attempts have been made to reinforce such seams, so as to make them as strong as the mainportion of the metal Walls. One method is to cause a sheet-metal reinforcingstrip to interlock with the turned edges of the metalwalls.v Another'way'of reinforcing is to form an ordinary interlocked seam and build up a thick reinforcing-ridge of solder over the seam. None of these -methods have been found adequate in practice, as the seams. usually part at high pressures before the limit of strength of the sheet metal has been reached. The difficulty is that the separatingstrains exerted on the edges of the metal tend to unfold the seam, and when the solder once gives away at one point the action is progressive or of a tearing nature and the seam is easily disrupted, the reinforcement being of insufficient strength or not applied in aproper manner to withstand the strain on the seam. I overcome those difficulties by soldering the main wall portions of the receptacle on both sides of the seam to a rigid reinforcing'meinber of sufficient stiffness to withstand the strains which tend to unroll the seam, and by thus transferring the strains to this member I relieve the seam and prevent it from parting.

Of the accompanying drawings, Figure l represents a longitudinal sectional view of a .receptacle constructed according to my invention. Fig. 2 represents a section on line 2 2 of Fig. l on an enlarged scale. Fig. 3 represents a perspective view of the reinforcing member. Fig. 4 represents a perspective view of the joint, partly in section, on line 4 4 of Fig. 1. Fig. 5 represents a plan View of the seam and reinforcing member separated. Fig. 6 represents an enlarged section al view of the joint, showing the solder.

The same reference characters indicate the same parts in all the figures.

In the drawings, 1 represents a receptacle, such as the body ofA a fire-extinguisher, whose Walls are made of sheet metal, the meeting edges of which are bent to make an interlocked or double -lapped seam 2, forming a longitudinal bead or ridge on the inside of the receptacle. The meeting edges are tinned in the usualmannerbefore the seam isformed, so that when heat is applied the solder will flow and unite the portions ofthe seam.

3 is a reinforcing member or bar applied to the seam 2 and made of suliicient inherent stiffness to remain rigid under all bursting pressures to which the receptacle may be subj ected within the limits of the reasonable strength of its sheet-metal walls, said bar having a ridge 4 on its back to strengthen it, and also having a recess 5 of sufficient size to admit the inwardly-projecting seam and side portions or'flanks abutting the body walls on both sides of the seam. l

After the member ffly has been applied in place it is soldered to the seam 2 and to the immediately-adjacent portions of the walls of the receptacle, preferably by the method of sweating, which consists in heating the parts whose adhering surfaces have been previously tinned, until the solder flows and unites all the opposing surfaces. The solder is shown at 6 in Fig. 6. It is evident that the disrupting strains due to pressure within the vessel,

which are mainly exerted on the seam circumvferentially of the receptacle l, whereby the united edges of its sheet-metal walls tend to pull apart and unroll the seam 2, are transmitted from the portions of said walls on either side of the seam directly to the reinforcing member 3 through the solder which unites said portions to the flanks of said member. The seam itself is thereby to a large extent relieved'from the disrupting effect of these strains and prevented from unrolling. Such reinforcing effect'is also supplemented by the fact that the seam itself within the recess 5 is united to the walls of said recess by the solder, and the seam is confined and pre- IOO having Hanks abutting the receptacle-Walls on both sides ofthe seam, and solder uniting the seam to the middle portion of said member and uniting said Hanks to the laterallyadjacent Wal] portions, whereby strains tending to separate the united wall portions are borne mainly by the reinforein g member and not by the seam.

In testimony whereof I have affixed my signature in presence of two Witnesses.

ARTHUR C. BADGER.

. 'itnesses: A

R. M. PIERsoN, P. W. PEZZETTI. 

